1. Field of the Invention
The present invention relates to a smoke-generating redox composition containing one or more colophony or hydrogenated colophony ester derivatives.
The aim of the present invention is to provide a smoke-generating composition which satisfies the following specifications:
the products used to make the smoke-generating composition, namely the combustion oxidizing agent, the combustion reducing agent and the smoke-generating agent, are nontoxic in the concentrations and the exposure times used,
during its combustion, the smoke-generating composition generates an opaque smoke consisting of liquid and solid particles in the range from about 0.4 xcexcm to about 0.7 xcexcm in size,
on cooling, the liquid particles crystallize and become invisible after deposition,
the combustion particles do not adversely affect any material, such as textiles, or any equipment, in particular computer equipment.
2. Description of the Prior Art
Smoke-generating compositions which generate an opaque smoke by combustion include compositions based on terephthalic acid which are nontoxic but generate visible dusts and compositions based on colophony which are toxic but do not generate a visible deposit after combustion.
The present invention relates to a relatively nontoxic smoke-generating composition which leaves no visible deposit on objects after the smoke-generating agent has been fired off, which is particularly useful for firing off smoke-generating agents in a closed vessel, in particular when the smoke-generating agent is used in an alarm device or for checking the leaktightness of pipes.
More specifically, the present invention consists in a smoke-generating redox composition containing a combustion oxidizing agent, a combustion reducing agent and a smoke-generating agent which generates particles during its combustion and contains one or more colophony or hydrogenated colophony esters.
In the context of the present invention, the term xe2x80x9ccolophonyxe2x80x9d means the resinous residue from the distillation of terebenthine, which includes the oily resins extracted from conifers, in particular from the species Pinus maritima, Pinus palustris, Pinus australis and Pinus caribaea. 
Colophony is a mixture of diterpenic acids consisting of
about 90% of resinous acids of empirical formula C20H30O2, the main isomers of which are abietic acid, levopimaric acid and dextropimaric acid, of structural formulae 
about 10% of a mixture of dihydroabietic acid of empirical formula C20H32O2 and dehydroabietic acid of empirical formula C20H28O2, of structural formulae 
Abietic acid is the main constituent of colophony.
In the context of the present invention, the term xe2x80x9chydrogenated colophonyxe2x80x9d means the result of the hydrogenation of colophony, which is a hydrogenated mixture of the preceding diterpenic acids.
The hydrogenated abietic acid of formula 
is the main constituent of hydrogenated colophony.
The smoke-generating composition according to the invention contains one or more colophony or hydrogenated colophony esters. The ester(s) is (are) obtained from colophony or hydrogenated colophony and an alcohol, which is preferably a polyol.
The polyol is advantageously chosen from glycerol and pentaerythritol.
The smoke-generating composition of the invention also contains a combustion oxidizing agent preferably chosen from chlorates, for instance potassium chlorate.
The smoke-generating composition of the invention also contains a combustion reducing agent, preferably lactose.
The smoke-generating composition advantageously contains 30% to 55% by weight of smoke-generating agent, 25% to 40% by weight of combustion oxidizing agent and 20% to 30% by weight of combustion reducing agent.
One aspect of the present invention is the use of the smoke-generating composition described above for checking the leaktightness of ducts, in particular flues and tunnels.
Another aspect of the present invention is the use of the smoke-generating composition described above in a deterrent device, in particular an anti-intrusion alarm system.
Finally, the present invention is useful in smoke identification tests, in particular fire detection tests.